Meter-proving method and apparatus

ABSTRACT

Meter-proving method and apparatus for calibrating liquid flow metering devices. It employs a metering pipe or loop through which the flow is diverted. A plug or sphere is launched into the inlet end of the pipe and is propelled through the pipe by the liquid flow during a proving run. A special sphere-launching device is provided to launch the sphere into the inlet end of the metering pipe, and also to retain the sphere after it has cleared the pipe, whereby it is ready for the next prover run. This device is constructed to establish seals between the inlet and outlet ends of the proving pipe during and after a run. Its inner shuttle part is movable between sphere retaining and launching positions, and in both positions line flow occurs directly through the device. The inner shuttle part can be withdrawn for replacement of a sphere. Leak detecting means is associated with the seals of the device to detect any leakage.

United States Patent Grove et al.

[ 1 Feb. 1, 1972 i541 METER-PROVING METHOD AND APPARATUS [72] Inventors:Marvin 11. Grove; Lyle R. Van Arsdale,

both of Houston, Tex.

[73] Assignee: M & J Valve Company, Houston, Tex.

[22] Filed: Apr. 9, i970 [21] Appl. No.: 26,834

[52] U.S. Cl ..73/3

[51] Int. Cl. ..G0ll 25/00 [Sill FieldoiSeareh ..73/3. M5, l5/l04.6A

l Sol ltelerenees Cited UNITED STATES PATENTS 3,504,523 4ll970 Layhe..73/3 3,541,837 ll/l970 Davis et al. ..73/3 3,295,357 lll967 Halpine etal ..73I3

Primary ExaminerLouis R. Prince Assistant Examiner-William A. Henry, IIAttorney-Flehr, Hohbach, Test, Albritton & Herbert Meter-proving methodand apparatus for cnlihrntmg liquid flow metering devices. It employs ametering pipe or loop through which the flow is diverted. A plug orsphere is launched into the inlet end of the pipe and is propelledthrough the pipe by the liquid flow during a proving run. A specialsphere-launching device is provided to launch the sphere into the inletend of the metering pipe, and also to retain the sphere after it hascleared the pipe, whereby it is ready for the next prover run. Thisdevice is constructed to establish seals between the inlet and outletends of the proving pipe during and after a run. Its inner shuttle partis movable between sphere retaining and launching positions, and in bothpositions line flow occurs directly through the device. The innershuttle part can be withdrawn for replacement of a sphere. Leakdetecting means is associated with the seals of the device to detect anyleakage.

ABSTRACT 12 Claims, 9 Drawing Figures I i i PAIENIEB FEB H972 SHEEI 1 BF6 ()RS VE I SDALE INVENT MARVIN H. GRO

LYLE R. VAN AR 65 ATTORNEYS PATENTED FEB H872 3 '638'475 SHEU 2 [IF 6INVENTORS MARVIN H. GROVE LYLE R. VAN ARSDALE ATTORNEYS PATENTEU FEBH972 3,638,475

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52 3 :23 332 222w 252 2 :23 E0: uoucuEEou ucoEEou 2 2 22 6 m ol METER-PROVING METHOD AND APPARATUS BACKGROUND OF THE INVENTION This inventionrelates generally to flow meter proving methods and apparatus such asare employed in conjunction with pipe line transmission systems.

In connection with piping systems for conveying various liquid petroleumproducts, it is important to provide accurate flow-metering means.Conventional flow-metering devices of the positive displacement orturbine types are subject to serious inaccuracies that may becumulative. For this reason it is common to use so-called meter proverswhich make accurate periodic checks of the flow for calibration of themeter. A conventional form of meter prover consists of an extendedlength of metering pipe of uniform internal diameter and through whichthe main flow of the piping system can be directed. Some means isemployed to enable a plug or sphere to be launched into the inlet end ofthe metering pipe whereby it is propelled by flow through the pipe tothe outlet end thereof, where it is available for relaunching into theinlet end. As shown in U.S. Pat. No. 3,387,483, the means for launchingand retrieving the plug or sphere may be in the form of an interchangeprovided with valves through which the sphere may pass before reaching alaunching position. By means of an associated electrical system which isactivated when the sphere passes through sphere-detecting stations nearthe inlet and discharge ends, a flow meter reading is obtained for thetime interval which is required for the travel of the sphere between thedetecting points. This reading is then taken together with the knowncalculated volume of the metering pipe between the detecting points toprovide accurate calibration data. It is characteristic of such meterprovers that the sphere is launched through a tee which is connected tothe inlet end of the metering pipe. With such meter provers, it isimportant to prevent any leakage between the inlet and outlet ends ofthe metering pipe during a metering run, because such leakage interfereswith the desired accuracy.

Prior meter-proving methods and apparatus are subject to a number ofdisadvantages. Particularly, the interchange is relatively expensive,and its design characteristics complicate and make installation of acomplete meter prover system expensive. Although the interchange may beconstructed as disclosed in US. Pat. No. 3,387,483, thereby minimizingtransfer of undesired sludge solids back into the inlet end of themetering pipe, this difficulty is not entirely alleviated, because anysludge solids which are permitted to pass through the interchange arerecirculated through the metering pipe. Sludge or other foreign solidspresent in the liquid passing through the metering pipe interferes withproper movement of the sphere, and thus interferes with the desiredaccuracy.

SUMMARY OF THE INVENTION AND OBJECTS An object of the present inventionis to provide a meterproving method and apparatus characterized by asimplified procedure and device for receiving the sphere at the end ofarun and for relaunching the sphere into the inlet end of the meteringpipe.

Another object of the invention is to provide a method and apparatus ofthe above character which avoids the use of a connecting tee inlaunching the sphere into the inlet end of the metering pipe.

Another object is to provide a meter prover method and apparatus havingnovel means for retrieving the sphere after a run.

Another object of the invention is to provide an apparatus of the abovecharacter having a novel device for retrieving the sphere and forrelaunching it into the metering pipe, the device being characterized bysimplicity of construction and operation, and by the fact that the lineflow occurs directly through the same.

Another object of the invention is to provide a meter-proving method andapparatus having novel provision for detecting any leakage which wouldinterfere with metering accuracy.

In general, the present method makes use of a length of metering pipethrough which the normal flow of a piping system can be diverted. Thismetering pipe is adapted to receive a sphere whereby the sphere ispropelled through the metering pipe between predeterminedsphere-detecting points. Before commencing a metering run, the sphere isloosely retained in a movable shuttle part which is disposed within anenclosed body. Both the shuttle part and the body form parts of asphere-launching device. To start a run, the shuttle part is shiftedfrom a first to a second position which brings the sphere into alignmentwith inlet and outlet passages in the body. These passages are connectedto the upstream side of the piping system, and to the inlet end of themetering pipe. Thus normal line flow propels the sphere into and throughthe metering pipe and past the detecting points, with delivery from theoutlet end of the metering pipe back to the launching device. In thisposition of the sphere (either within or adjacent to the shuttle part),the main line flow continues about the sphere through the shuttle partto the downstream side of the piping system, until the shuttle part andsphere are again shifted to commence a metering cycle. At thecommencement of and during the making of a metering run, the operatormay detect any leakage between the inlet and outlet ends of the meteringpipe. The leak-detecting means functions in conjunction with specialsealing means between the movable part and the closed body.

Additional objects and features of the invention will appear from thefollowing description in which the preferred embodiment has been setforth in detail in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a plan view illustratingmeter-proving apparatus in accordance with the present invention.

FIG. 2 is a side elevational view showing the apparatus of FIG. I.

FIG. 3 is an end view of the metering apparatus, looking toward theleft-hand end of FIG. 2.

FIG. 4 is a cross-sectional detail in section showing thesphere-launching device and its connections to the metering loop and theupstream sides of the piping system.

FIG. 5 is a view similar to FIG. 4 but showing the shuttle part of thelaunching device in another operating position.

FIG. 6 is an enlarged detail in section showing one of the sealingassemblies and ducts for making connection to the exterior of thedevice.

FIG. '7 is a schematic view illustrating means connected to the sealingassemblies for detecting leakage.

FIG. 8 is a block diagram schematically illustrating an electricalsystem for automating the sphere-launching device.

FIG. 9 is a diagram illustrating a complete automated cycle for theapparatus, the cycle starting with the shuttle part in sphere-catchingposition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus illustrated inthe drawing consists of a metering pipe I0 which is generally in theform ofa loop having inlet and outlet end portions 11 and 12. Theseportions are shown equipped with sphere-detecting devices 13 and I4which serve to indicate passage of a sphere into and out of the pipe.The special sphere handling or launching device 16 is interposed betweenthe inlet and outlet end portions of the pipe. Thus a bend connection 17is made between device 16 and the inlet end portion II, and a pipesection 18 of enlarged internal diameter connects the outlet portion 12with device 16. Also device 16 has a direct flow connection 19 with theupstream side of the main piping system, and another connection 2! withthe downstream side of the main piping system. A suitable constructionfor the devices 16 is shown in FIGS. 3, 4, and 5. It consists of aclosed body 22 which is boxlike in transverse section, and may befabricated from steel plate by welding. Thus flat parallel end walls 23and 24 may be connected by welding to the flat parallel sidewalls 26.Plate 27 serves to close one end of the body. A second closure plate 28is shown removably secured (as by bolts not shown) to the flange 29 onthe other end ofthe body.

The end wall 23 is provided with an inlet flow passage 29 which connectswith the upstream piping 19. The end wall 24 has a flow passage 31 whichis aligned with the passage 29 and which connects with the pipe bend 17and the portion 11 of the metering pipe. Within the closed body there isa shuttle part 32 which can be constructed of plates 33 welded to theends of the sphere-accommodating portion 34, which may be annular insection.

Seat rings 36 are mounted on the end walls 23 and 24, and generallysurround the flow passages 29 and 31. Each seat ring is provided with asealing assembly 37 which is preferably made of resilient material andconstructed as will be presently described in detail.

The two operating positions of the shuttle part 32 are shown in FIGS. 4and 5. In FIG. a sphere 38 of the kind used with meter provers is shown(dotted lines) accommodated in the space 39 within the shuttle part. Thedimensions are such that line flow can readily occur about the sphere.For the position of the shuttle part shown in FIG. 4, the space 39 inthe shuttle part is in registry with the flow passages 29 and 31, andthere fore the sphere is in position to be launched by fluid flow intothe inlet end of the metering pipe. The sphere is shown in dotted linesbeing moved by fluid flow into the bend 17 leading to the inlet portion11 of the metering loop 10.

Power means is shown for moving the shuttle part 32 between the twooperating positions described above. While various types of operatingdevices can be used, we prefer to employ an operator of the hydraulictype. Thus a hydraulic cylinder 41 is shown mounted upon the closureplate 28, and is provided with a fluid pressure operated pistonconnected to the operating rod 42. The end of this rod is provided witha head or nut 43 which is normally accommodated within a recess 44formed in the lug 45. This lug is shown fixed to the shuttle part bywelding. It will be evident that by supplying hydraulic liquid to oneend of the hydraulic cylinder 41 while exhausting liquid from the otherend of the cylinder, the shuttle part can be shifted between its twooperating positions. For the position shown in FIG. 4 rod 42 serves as asphere-detaining means whereby a sphere is detained from entering thebody 22 until the shuttle part is moved to the position of FIG. 5.

The end walls 23 and 24 of the body 22 are also provided with inlet andoutlet flow passages 48 and 49. Passage 48 connects with the outlet endof the metering pipe, while passage 49 (and pipe section 21) connects tothe downstream side of the main piping system. Bars 51 are mounted onthe end wall 24 within the passage 49 and form sphere-detaining meanswhereby a sphere is retained in space 39 for the position ofthe shuttleshown in FIG. 5.

Referring to FIGS. 4 and 5, it is desirable to provide ribs 53 in theflow passage 48, and also ribs 54 within the shuttle space 39. Theseribs are spaced circumferentially and are dimensioned whereby they guideand generally centralize a sphere. Also they effectively guide a sphereas it passes out of the meter loop through passage 48 and into theshuttle part.

From time to time it is desirable to remove and replace the sphere. Forthis purpose, the plate 28 is made slidable upon the guide rods 56 whichare fixed to the body 22. When the bolts securing the plate 28 to flange29 are removed, the plates 28 can be slid to the left as viewed in FIG.5 and shown in dotted lines, thus causing the shuttle part to bewithdrawn from the body for removal of a sphere from the space 39. Forconvenience, trackways 57 with hinged extensions 57:: can be providedadjacent the shuttle device for supporting spare spheres.

Although the apparatus can be installed in various positions, it isdesirable in many instances to install the loop horizontally as shown inFIG. 2, with the shuttle device likewise in a horizontal position forhorizontal movements of the shuttle part. Since flow occurs directlythrough the device 16. there is a washing out action which prevents theaccumulation of solid materials. Furthermore, there is no tendency forsolid material to be recirculated through the loop.

A desirable construction for each of the sealing assemblies 37 is shownin FIG. 6. This construction is also shown in copending application Ser.No. l7,365 filed Mar. 9. I970. It consists of a seat ring 61 made ofmetal and movably titted within a cylindrical bore 62 which forms a partof the accommodating recess 63. That end of the seat ring 61 adjacentthe plate 33 of the shuttle part is provided with a sealing assembly 64accommodated within the recess 66. The assembly consists of an annularmember 67 formed of material like nylon. together with more resilientmembers 68 and 69 which are in terposed between the inner and outerperipheries of the nylon ring and the adjacent peripheral surfaces ofthe recess 66. The faces 71 and 72 formed by the members 68 and 69 pressagainst the adjacent surface 73 of plate 33, thus forming fluidtightseals on spaced concentric areas. The nylon ring 67 is provided with agroove 74 which communicates with the duct 76. The seat ring 61 issealed with respect to the adjacent body part by the seal rings 77 ofthe resilient O-ring type. Circumferentially disposed compressionsprings 78 serve to urge the seat ring 61 and the sealing assemblyagainst the plate 33.

The duct 76 in the sealing assembly communicates to the exterior of thedevice through ducts 81 and 82 in the seat ring 61 and duct 83 in theadjacent portion of the body. By means of fitting 84 on the exteriorside of the body, a tube or pipe 86 may be in communication with duct 83and is employed for determining any leakage occurring past the sealingassemblies immediately preceding and during a metering run. Briefly, ifboth faces 71 and 72 are effectively establishing seals with the surface73 of the plate 33 for both sides of the shuttle part, then if tube 86is opened to the atmosphere no liquid will be discharged except for asmall amount that may be trapped between the two sealing areas duringmovement of the shuttle part between its operating positions. if leakageis occurring past a sealing assembly, then after venting thecorresponding pipe 86 to the atmosphere, some pressure buildup will benoted when the pipe is closed.

To facilitate detection of leakage at a remote station, the arrangementshown in FIG. 7 can be employed. Here the fittings 84 for the twosealing assemblies are connected to pipelines 91 and 92 which arecontrolled by the small electrically operated vent valves 93 and 94.When the winding of one of these valves is energized, it connects theassociated line 91 or 92 to the atmosphere for a limited period of timewhereby pressure in the line is reduced to atmospheric. Thereafter theline is closed and any pressure rise noted. Pressure rise can be notedby the electrically operated switches 96 and 97 which are likewiseconnected to lines 91 and 92. The energizing circuit for the windings ofvent valves 93 and 94 may lead to a remote station as indicated, whereit is controlled by closing the switch 98. The contacts of thepressure-operated switches 96 and 97 are preferably connected in serieswith a circuit which includes the indicating means 99 which may be asignal lamp. Thus at the beginning of a run, the operator at the remotestation temporarily closes a switch 98, whereby the vent valves 93 and94 are energized for a short period to open both lines 91 and 92 to theatmosphere. Thereafter both lines are closed but are in communicationwith the pressureoperated switches 96 and 97. If there is a pressurebuildup in both sealing assemblies before the run is commenced, or itsuch a buildup occurs during a metering run, it is indicated by thedevice 99.

The indicating means described above is desirable in that it requiresventing of only relatively small amounts of liquid from the spacesbetween the sealing areas. It indicates a leakonly if both sealingassemblies are leaking, since both assemblies must leak to cause leakageof liquid between the inlet and outlet portions of the loop.

Operation of the apparatus described above is as follows. It is assumedthat a sphere is within the space 39 of the shuttle part, and that theshuttle part is moved to the position shown in FIG. 4. Assuming now thatflow is diverted from the main piping system into the inlet passage 29,the sphere is carried through the flow passage 3i and into the inlet endof the metering loop. As the sphere passes the detecting device 13, asignal pulse starts the run, and thereafter the sphere is propelledthrough the metering loop to the outlet end portion. When the sphereoperates detector [4, the shuttle part 32 is moved back to the positionshown in FIG. 5 whereby the space 39 is positioned in alignment with theflow passage 48. At the termination of the run the sphere is receivedwithin space 39 and comes to rest in engagement with the bars 54. Inthis position, flow may continue about the sphere into the downstreamside of the main piping system. At the beginning of a new metering run,the shuttle part 32 is again moved back to the position shown in FIG. 4which again brings the sphere into alignment with the passage 31 wherebyit is again launched into the metering pipe. At the beginning the run,or in other words, immediately after the shuttle part has beenpositioned as shown in FIG. 4, the operator may determine whether or notthere is any leakage by operating the vent valves 93 and 94 andobserving whether or not there is any buildup of pressure in both of thesealing assemblies, which is noted by the indicating device 99. If apressure buildup does occur in both sealing assemblies during the run,then the closing of the pressureoperated switches 96 and 97 operates theindicating device 99.

If it becomes necessary to replace a sphere, the plate 28 is unboltedfrom the body 22 and then withdrawn to the dotted line position shown inFIG. 5, whereby the sphere is made accessible for removal from space 39.After replacing the sphere, the parts are returned to bring the shuttlepart into the position shown in FIG. 5, after which plate 28 is againsecured to the flange 29.

It will be evident from the foregoing that we have provided ameter-proving method and apparatus having many advantages over deviceswhich have been used in the past. The spherelaunching device isrelatively simple in construction and operation, and greatly simplifiesthe launching of a sphere after it is retrieved at the end of a meteringrun. The spherelaunching device avoids the necessity of using twoseparate gate valves as with the apparatus shown in US. Pat. No.3,387,483. Accumulation of solid material in the metering loop and inthe connecting means is avoided because the direct flow of liquidthrough the launching device washes out any solids tending to accumulatetherein and avoids recirculation ofsuch solids through the loop.

ln explanation of the appended claims, the flow passages 29 and 31 canbe referred to as first and second passages, and flow passages 48 and 49as third and fourth passages.

It is desirable to provide an electrical system for automating operationof the apparatus whereby when initiated by an operator the apparatuswill carry out a complete proving cycle. A block diagram of such anelectrical system is shown in FIG. 8. The parts of the systemillustrated in FIG. 8 consist of an electronic gate 101, a bistableelectronic switch 102, an electronic timer 103, a so-called inhibitorI04, and an electronic timer 105. It is assumed that the electronicpower supply 106 supplies current to all of the circuitry. Apowendetecting gate 107 is interposed between the power supply and thebistable switch 102.

The schematically illustrated sphere-handling device 16 is shown havingits power operator 4! with hydraulic connections through the four-waycontrol valve 111, with this valve in turn operated by the solenoids112, 113 or other motive meansv Solenoids I12 and US are selectivelyoperated by commands from the bistable switch 102 as indicated, and thecondition of this switch is controlled by commands as will be presentlyexplained.

The electronic gate l0] is controlled by commands from both theinhibiting device I04 and the timer 103. Also it is controlled by acycle-initiating command as indicated by line 1 14. Lines I16 and 117represent commands from the bistable switch 102 to the solenoids H2, M3for operating the shuttle of device 16 between its sphere catching andlaunching positions. Line 118 represents a command from the spheredetector 14 to the bistable switch 102. Line "9 represents a commandfrom a limiting switch associated with the operating rod for the shuttlepart and which functions when the shuttle part is moved tosphere-catching position. Line 121 represents a command from anotherlimiting switch associated with the shuttle part and which is applied tothe timer when the shuttle part is moved to its sphere-launchingposition.

FIG. 8 also shows substantially the same leak-detecting means as in FIG. 7. The solenoid-operated vent valves 93 and 94 are connected to thepipelines 91 and 92 which in turn connect with the spaces between thedual sealing areas. The pressure-operated switches 97 and 98 have theircontacts connected in series with the circuit leak indicating circuit.Line 122 represents a command from the timer 105 to the switch means 123which serves to energize the solenoid-operated vent valves 93 and 94.

The power supply [06 supplies all of the circuitry of the system, asindicated byline I24. The gate 107 supplies a command represented byline on the application of power, to force the bistable switch 102 intoa condition corresponding to sphere-catching position of device 16.

Operation of the electronic system illustrated in FIG. 8 is as follows.A manual command is not transmitted to the bistable switch 102 if thegate 101 is closed by a blocking command from the inhibiting device I04and timer 103. Assuming that the command is transmitted through the gatel0], then bistable switch [02 moves to a condition in which it issues acommand through line 116 to condition the four-way control valve Ill tosupply hydraulic liquid to the operator 4] in such a manner as torapidly move the shuttle part from spherecatching to sphere-launchingposition. The sphere is now launched into the inlet end of the meteringpipe, and the meter-proving run is commenced when the sphere passes thefirst detector 13. When the sphere passes the second sphere detector 14,a command 118 is applied to the bistable switch 102 which in turnsupplies a command through line 117 to cause the hydraulic operator 41to move the shuttle part back to sphere-catching position. At the timethe shuttle part is first moved to the sphere-launching position, itslimiting switch causes a command 121 to be sent to the timer I05 and tothe switch 123 to cause the solenoid valves 93 and 94 to be immediatelyenergized for a short period to vent the spaces between the sealingareas of the sealing assemblies. After a predetermined short period ofventing time, both solenoid valves are reclosed before the spherereaches the first detec tor, and thereafter any leakage past bothassemblies will cause the pressure switches 97 and 98 to be operated toclose the leak-detecting circuit. At the time the bistable switch ")2sends a command through line 117 to cause the hydraulic operator 42 tomove the shuttle part back to sphere-catching position, a command isalso sent to the inhibiting device 104 whereby this device sends ablocking command to the gate 102, thus blocking any further commands toinitiate a new proving cycle. When the shuttle part has completed itsmovement to sphere-catching position, a limiting switch sends a command119 which sets the timer 103 in operation, and at the same timereconditions the inhibiting device 104 whereby the blocking commandpreviously applied by this device to gate 101 is removed. Timer 103provides a small time interval following movement of the shuttle part tosphere-catching position to ensure that the sphere is within the shuttlepart before a new proving cycle can be initiated.

The cycle of operation described above with reference to FIG. Sisgraphically illustrated in FIG. 9. The right-hand vertical lines of thisfigure represent operating positions of various parts. The upper part ofthe figure represents the completion. The left-hand portion of thefigure consists of legends explaining various stages of the cycle byreference to the positioning of parts as represented by jogs in thevertical lines. It will be seen that the cycle begins with a command toinitiate a proving cycle, at which time the shuttle part is in thespherecatching position. The next step in the automated cycle is for theshuttle part to commence rapid movement from its spherecatching positionto the sphere-launching position. The next step is to initiate operationof the vent valves 93 and 94 of the leak detector means immediately whenthe shuttle part reaches launching position. The next step is for thelaunched sphere to pass the first sphere detector, which represents thebeginning of a prover run. The next step is for the sphere to reach thesecond sphere detector, which causes a command to be applied to commencereturn movement of the shuttle part from launching to sphere-catchingposition. The next step is for the shuttle part to reach sphere-catchingposition, and this causes a command to be applied which preventsapplication of a command to start a new run until the sphere is safelywithin the shuttle part. The next phase is for the timer 103 to reachthe end ofits timing period, thereby conditioning the gate 101 toreceive a new command and to initiate a new cycle. Application of such anew command is indicated at the bottom of the figure.

The automated cycle described above has a number of desirable features.The cycle makes unnecessary the use of a detent pin for releasing thesphere after it is launched by the device 16. Leak detection is carriedout after the sphere has moved to launching position and started on itspath of movement into the proving pipe, thus proving a leak detectionimmediately before the sphere reaches the first sphere detector, asdistinguished from initiating a venting operation to detect leaks beforethe cycle is commenced. This is made possible because of the relativelysmall amount of liquid which is vented from the dual sealing areas, aspreviously described in connection with FIG. 7.

We claim:

1. A meter-proving method making use ofa length of metering pipe throughwhich the flow of a piping system can be diverted and adapted to receivea sphere that is propelled through the metering pipe betweenpredetermined sphere-detecting points by liquid flow, the steps ofloosely retaining a sphere in a movable shuttle part that is enclosedwithin a body, shifting the shuttle part from a first to a secondposition in which the sphere is in alignment with inlet and outlet flowpassages in the body, directing flow from the upstream side of thepiping system through the inlet flow passage to cause the sphere to belaunched into the inlet end of the metering pipe and propelledtherethrough, causing the sphere to be delivered directly from theoutlet end of the metering pipe to a third inlet flow passage in thebody and into the shuttle part while flow is maintained through theshuttle part and about the sphere, causing said last-named flow to bedelivered to the downstream side of the piping system through a fourthflow passage in the body, and then again shifting the shuttle part andthe sphere into alignment with the first-named passages for relaunchingthe sphere.

2. A method as in claim 1 in which any leakage of liquid directlybetween the inlet and outlet ends of the metering pipe is detected afterthe sphere is launched and before it reaches the first detector.

3. A meter-proving apparatus comprising a spherelaunching device, saiddevice consisting of a body, first, second, third and fourth flowpassages in the body, the first and second flow passages being inalignment, and the third and fourth flow passages likewise being inalignment, a shuttle part movable between two limiting positionsdisposed within the body, said shuttle part having asphere-accommodating space which is brought into alignment with thefirst and second flow passages, or the third and fourth flow passages,for the two limiting positions, a meter-proving pipe, a connectionbetween the second flow passage and the inlet end portion of themetering pipe, means forming a connection between the third flow passageand the outlet end portion of the metering pipe, means forming aconnection between the upstream side of the main piping system and thefirst flow passage, means forming a connection between the fourth flowpassage and the downstream side of the main piping system, and means forshifting said shuttle part between said two operating positions, in oneof which said space is in alignment with the first and second flowpassages, and in the second of which said space is in alignment with thethird and fourth passages.

4. Apparatus as in claim 3 together with sealing means interposedbetween the side portions of said shuttle part and the end walls of thebody, said sealing means being carried by said end walls and generallysurrounding said first and second flow passages.

5. Apparatus as in claim 3 together with bonnet means forming a closurefor one extremity of the body, said bonnet means being removable topermit withdrawal of the shuttle part from the body.

6. Apparatus as in claim 3 together with power means for moving theshuttle part between its operating positions, said power means includingmotive means. a rod connecting said motive means with said shuttle part,said rod extending substantially across said third flow passage when theshuttle part and said sphere-receiving space are in alignment with thefirst and second flow passages.

7. A sphere-launching device for use with meter provers of the typeincluding a meter-proving pipe having inlet and outlet end portions andadapted to receive a flow-propelled sphere, said device comprising abody having opposed end walls having first, second, third and fourthflow passages in the same, the first and second passages being inalignment and the second and third passages likewise being in alignment,the first passage being adapted to communicate with the upstream portionof a liquid piping system and the second fiow passage being adapted tocommunicate with the inlet end portion of the metering pipe, the thirdflow passage being adapted to communicate with the outlet end portion ofthe metering pipe, and the fourth flow passage being adapted tocommunicate with the downstream side of the piping system, a shuttlepart disposed within the body and movable between first and secondoperating positions, said shuttle part including a portion providing aspace for accommodating a sphere, means forming sealing assembliessurrounding the first and second flow passages when the shuttle part isin its first operating position, said sealing assemblies formingfluidtight seals between the body and the shuttle part, saidsphere-accommodating space being in alignment with the first and secondflow passages when the shuttle part is in said first operating positionand likewise being in alignment with the third and fourth passages whenthe shuttle part is in its second operating position, said shuttle partwhen in said first operating position permitting a sphere carried by thesame to be launched into the inlet end portion of the metering pipe andwhen in said second operating position serving to receive a spheredelivered from the outlet end portion of the metering pipe, and meansfor shifting the shuttle part between said first and second operatingpositions.

8. A sphere-launching device as in claim 7 in which the body is in theform of a box that is rectangular in section having end walls in whichthe said flow passages are formed and in which the shuttle part consistsof spaced plates extending parallel to said end walls and secured to theends of said portion forming said sphere-receiving space,

9. A sphere-launching device as in claim 8 together with power means formoving said shuttle part between said two operating positions and bonnetmeans mounted on one extremity of the body and serving to carry saidpower means, said power means including an operating rod having one endof the same mechanically coupled to the shuttle part.

10. A device as in claim 9 in which said bonnet means is detachable topermit removal of the shuttle part.

11. A device as in claim 9 in which said rod extends across said thirdflow passage to block passage of a sphere through the same when theshuttle part is in said first position.

12. A meter-proving method making use of a length of meter-proving pipethrough which the flow of a piping system can be diverted and adapted toreceive a sphere that is propelled through the metering pipe betweenpredetermined sphere-detecting points by liquid flow, there being aspherehandling device to which the ends of the metering pipe areconnected, the device having a shuttle part which can be moved to onelimiting position for receiving and retaining a sphere being dischargedfrom the metering pipe and being movable to a second limiting positionwhere the sphere is launched into the inlet portion of the meteringpipe, the method comprising the following steps carried out in sequence.commencing with the sphere within the shuttle part, shifting the shuttlepart from sphere-catching to spherelaunching position to cause thesphere to enter the inlet portion of the metering pipe, initiating aleakage detection operation immediately after the shuttle part has movedto spherelaunching position and before the sphere has reached the firstsphere detector, said leak-detecting operation serving to determinewhether or not any leakage is occurring directly between the inlet andoutlet ends of the metering pipe through said sphere-handling device,commencing the proving run when the sphere passes the first spheredetector. completing the run when the sphere passes the second spheredetector, causing the shuttle part to be moved back to itsspherecatching limiting position with such movement being commenced whenthe sphere passes said second sphere-detecting point and then inhibitingthe commencement of a new prover cycle for a predetermined time afterthe shuttle part has been returned to sphere-catching position therebyensuring proper positioning of the sphere within the shuttle part beforethe commencement of a new proving cycle.

1. A meter-proving method making use of a length of metering pipethrough which the flow of a piping system can be diverted and adapted toreceive a sphere that is propelled through the metering pipe betweenpredetermined sphere-detecting points by liquid flow, the steps ofloosely retaining a sphere in a movable shuttle part that is enclosedwithin a body, shifting the shuttle part from a first to a secondposition in which the sphere is in alignment with inlet and outlet flowpassages in the body, directing flow from the upstream side of thepiping system through the inlet flow passage to cause the sphere to belaunched into the inlet end of the metering pipe and propelledtherethrough, causing the sphere to be delivered directly from theoutlet end of the metering pipe to a third inlet flow passage in thebody and into the shuttle part while flow is maintained through theshuttle part and about the sphere, causing said lastnamed flow to bedelivered to the downstream side of the piping system through a fourthflow passage in the body, and then again shifting the shuttle part andthe sphere into alignment with the first-named passages for relaunchingthe sphere.
 2. A method as in claim 1 in which any leakage of liquiddirectly between the inlet and outlet ends of the metering pipe isdetected after the sphere is launched and before it reaches the firstdetector.
 3. A meter-proving apparatus comprising a sphere-launchingdevice, said device consisting of a body, first, second, third andfourth flow passages in the body, the first and second flow passagesbeing in alignment, and the third and fourth flow passages likewisebeing in alignment, a shuttle part movable between two limitingpositions disposed within the body, said shuttle part having asphere-accommodating space which is brought into alignment with thefirst and second flow passages, or the third and fourth flow passages,for the two limiting positions, a meter-proving pipe, a connectionbetween the second flow passage and the inlet end portion of themetering pipe, means forming a connection between the third flow passageand the outlet end portion of the metering pipe, means forming aconnection between the upstream side of the main piping system and thefirst flow passage, means forming a connection between the fourth flowpassage and the downstream side of the main piping system, and means forshifting said shuttle part between said two operating positions, in oneof which said space is in alignment with the first and second flowpassages, and in the second of which said space is in alignment with thethird and fourth passages.
 4. Apparatus as in claim 3 together withsealing means interposed between the side portions of said shuttle partand the end walls of the body, said sealing means being carried by saidend walls and generally surrounding said first and second flow passages.5. Apparatus as in claim 3 together with bonnet means forming a closurefor one extremity of the body, said bonnet means being removable topermit withdrawal of the shuttle part from the body.
 6. Apparatus as inclaim 3 together with power means for moving the shuttle part betweenits operating positions, said power means including motive means, a rodconnecting said motive means with said shuttle part, said rod extendingsubstantially across said third flow passage when the shuttle part andsaid sphere-receiving space are in alignment with the first and secondflow passages.
 7. A sphere-launching device for use wiTh meter proversof the type including a meter-proving pipe having inlet and outlet endportions and adapted to receive a flow-propelled sphere, said devicecomprising a body having opposed end walls having first, second, thirdand fourth flow passages in the same, the first and second passagesbeing in alignment and the second and third passages likewise being inalignment, the first passage being adapted to communicate with theupstream portion of a liquid piping system and the second flow passagebeing adapted to communicate with the inlet end portion of the meteringpipe, the third flow passage being adapted to communicate with theoutlet end portion of the metering pipe, and the fourth flow passagebeing adapted to communicate with the downstream side of the pipingsystem, a shuttle part disposed within the body and movable betweenfirst and second operating positions, said shuttle part including aportion providing a space for accommodating a sphere, means formingsealing assemblies surrounding the first and second flow passages whenthe shuttle part is in its first operating position, said sealingassemblies forming fluidtight seals between the body and the shuttlepart, said sphere-accommodating space being in alignment with the firstand second flow passages when the shuttle part is in said firstoperating position and likewise being in alignment with the third andfourth passages when the shuttle part is in its second operatingposition, said shuttle part when in said first operating positionpermitting a sphere carried by the same to be launched into the inletend portion of the metering pipe and when in said second operatingposition serving to receive a sphere delivered from the outlet endportion of the metering pipe, and means for shifting the shuttle partbetween said first and second operating positions.
 8. A sphere-launchingdevice as in claim 7 in which the body is in the form of a box that isrectangular in section having end walls in which the said flow passagesare formed and in which the shuttle part consists of spaced platesextending parallel to said end walls and secured to the ends of saidportion forming said sphere-receiving space.
 9. A sphere-launchingdevice as in claim 8 together with power means for moving said shuttlepart between said two operating positions and bonnet means mounted onone extremity of the body and serving to carry said power means, saidpower means including an operating rod having one end of the samemechanically coupled to the shuttle part.
 10. A device as in claim 9 inwhich said bonnet means is detachable to permit removal of the shuttlepart.
 11. A device as in claim 9 in which said rod extends across saidthird flow passage to block passage of a sphere through the same whenthe shuttle part is in said first position.
 12. A meter-proving methodmaking use of a length of meter-proving pipe through which the flow of apiping system can be diverted and adapted to receive a sphere that ispropelled through the metering pipe between predeterminedsphere-detecting points by liquid flow, there being a sphere-handlingdevice to which the ends of the metering pipe are connected, the devicehaving a shuttle part which can be moved to one limiting position forreceiving and retaining a sphere being discharged from the metering pipeand being movable to a second limiting position where the sphere islaunched into the inlet portion of the metering pipe, the methodcomprising the following steps carried out in sequence, commencing withthe sphere within the shuttle part, shifting the shuttle part fromsphere-catching to sphere-launching position to cause the sphere toenter the inlet portion of the metering pipe, initiating a leakagedetection operation immediately after the shuttle part has moved tosphere-launching position and before the sphere has reached the firstsphere detector, said leak-detecting operation serving to determinewhether or not any leakage is occurring directly between the inlet andoutlet ends of the metering pipe through said sphere-handling device,commencing the proving run when the sphere passes the first spheredetector, completing the run when the sphere passes the second spheredetector, causing the shuttle part to be moved back to itssphere-catching limiting position with such movement being commencedwhen the sphere passes said second sphere-detecting point and theninhibiting the commencement of a new prover cycle for a predeterminedtime after the shuttle part has been returned to sphere-catchingposition thereby ensuring proper positioning of the sphere within theshuttle part before the commencement of a new proving cycle.